--- /dev/null
+/** PURE_IMPORTS_START tslib,_Subscriber,_util_EmptyError PURE_IMPORTS_END */
+import * as tslib_1 from "tslib";
+import { Subscriber } from '../Subscriber';
+import { EmptyError } from '../util/EmptyError';
+export function single(predicate) {
+ return function (source) { return source.lift(new SingleOperator(predicate, source)); };
+}
+var SingleOperator = /*@__PURE__*/ (function () {
+ function SingleOperator(predicate, source) {
+ this.predicate = predicate;
+ this.source = source;
+ }
+ SingleOperator.prototype.call = function (subscriber, source) {
+ return source.subscribe(new SingleSubscriber(subscriber, this.predicate, this.source));
+ };
+ return SingleOperator;
+}());
+var SingleSubscriber = /*@__PURE__*/ (function (_super) {
+ tslib_1.__extends(SingleSubscriber, _super);
+ function SingleSubscriber(destination, predicate, source) {
+ var _this = _super.call(this, destination) || this;
+ _this.predicate = predicate;
+ _this.source = source;
+ _this.seenValue = false;
+ _this.index = 0;
+ return _this;
+ }
+ SingleSubscriber.prototype.applySingleValue = function (value) {
+ if (this.seenValue) {
+ this.destination.error('Sequence contains more than one element');
+ }
+ else {
+ this.seenValue = true;
+ this.singleValue = value;
+ }
+ };
+ SingleSubscriber.prototype._next = function (value) {
+ var index = this.index++;
+ if (this.predicate) {
+ this.tryNext(value, index);
+ }
+ else {
+ this.applySingleValue(value);
+ }
+ };
+ SingleSubscriber.prototype.tryNext = function (value, index) {
+ try {
+ if (this.predicate(value, index, this.source)) {
+ this.applySingleValue(value);
+ }
+ }
+ catch (err) {
+ this.destination.error(err);
+ }
+ };
+ SingleSubscriber.prototype._complete = function () {
+ var destination = this.destination;
+ if (this.index > 0) {
+ destination.next(this.seenValue ? this.singleValue : undefined);
+ destination.complete();
+ }
+ else {
+ destination.error(new EmptyError);
+ }
+ };
+ return SingleSubscriber;
+}(Subscriber));
+//# sourceMappingURL=single.js.map